Gender differences in the incentive salience of adult and infant faces.

Facial appearance can motivate behaviour and elicit activation of brain circuits putatively involved in reward. Gender differences have been observed for motivation to view beauty in adult faces--heterosexual women are motivated by beauty in general, while heterosexual men are motivated to view opposite-sex beauty alone. Although gender differences have been observed in sensitivity to infant cuteness, infant faces appear to hold equal incentive salience among men and women. In the present study, we investigated the incentive salience of attractiveness and cuteness in adult and infant faces, respectively. We predicted that, given alternative viewing options, gender differences would emerge for motivation to view infant faces. Heterosexual participants completed a "pay-per-view" key-press task, which allowed them to control stimulus duration. Gender differences were found such that infants held greater incentive salience among women, although both sexes differentiated infant faces based on cuteness. Among adult faces, men exerted more effort than women to view opposite-sex faces. These findings suggest that, contrary to previous reports, gender differences do exist in the incentive salience of infant faces as well as opposite-sex faces.